I just installed 1/4" sheetrock on top of 1/2" sheetrock. Now I need advice on how to go about putting up the trim molding around the door and closet and not have that 1/4" gap between the door frame and molding.

You can replace the door frame with a wider board. Or you can try ripping a piece of trim filler to nail in the gap. It would be painted or stained to match, and be nailed in place along the length of the frame. Set it back from the edge of the frame just a bit and then set the trim back just a bit from that to have a stepped look.

I am looking for some assistance in installing wood trim. My wife and I are redoing our bathroom and want to install new trim. I am looking for help on the proper way to cut and install the trim so it will look its best.
I have did some trim in our old home but I just butted them together in the corners and it look bad.

Do you have a miter box? You do need something to help you cut the wood at a 45 degree angle.
All sorts of power tools and jigs I could describe and prescribe.. but for moulding and if you don't have a bunch of tools already, an inexpensive miter box is all you need.

Hmm tips. I cut the vertical pieces first, then the top (for the door) and then nail them in. NOTHING is ever perfectly square or perfectly cut, so this will allow you to make minor adjustments. Make your measurements from the outside of the miter.. the long ends of the boards.. and PAY attention to which way you are cutting the angles. If you are staining the trim, stain it all and put on your poly first... then cut the pieces to size. Also.. after a cut, stain the cut ends, then if there is a small gap, the wood inside will not be white and shining out.
Where possible cut through the part of the board which will face out to avoid splintering the face.

If you can... the best thing is to look at moulding that you like.. and try to match it.

What's the best way to hang crown molding? Can it be nailed directly to the wall and ceiling or is a supporting brace advisable? I plan to install crown molding in a room with textured walls and ceiling.

Crown molding should be nailed to the ceiling only, especially if you have roof trusses which have a tendency to lift up and down.

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We nailed ours to the wall, no reason to nail it to the ceiling. It really does not weigh much unless you are using that really heavy wide stuff then just add some glue to it also if you want.
With your textured walls I would be painting the ceiling then installing the crown molding (prefinished, just touch up the nail marks) Then fill the lower gaps with paintable caulking then paint the walls.
This gives you a nice finished edge when looking up.

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We could not do on the ceiling because it is a dropped ceiling with acoustical as well as the widest part on the molding itself was on the bottom not on the top edge so I guess it will all depend on your situation as well as the moldings style.

Crown molding

I am installing 3 inch crown molding. I have a compound miter saw but I do not know what the angles are for each cut. What are the angles? Is it better to bag cutting angles and just use a coping saw?

Set your saw at the typical 45 degrees for the miter and 22 1/2 degrees for the offset.

Installing Crown Molding

We are getting ready to install 2 piece crown molding. The one should be easy to install, I believe you just nail it flat to the wall. However, the piece that angles is 5 1/4 inch. What angles do you use to cut this? Also, in our bathroom, we will have do something when we get to our mirror because the mirror goes all the way to the ceiling. How do you make an end piece?

To make an end piece, you pretend it is turning a corner, but it is really turning into the wall. As far as the angle to cut it, there are two ways. The first is to put it into your miter-box or miter saw at the angle it goes on the wall, and then cut it from the top at a 45 degree angle. The second way is (harder) to check and see the angle it sits on your wall. Some crown molds go up on your wall at a 45 degree angle to the ceiling and the wall. Some of them go at a 30/60 degree. My miter saw has a little cheat sheet that tells me what angles I lay the mold
flat on my table bed in order to end up with a perfect corner joint, and it is all dependent on what angle it fits up into the ceiling/wall at. I am currently stalling on a project because my crown mold is about 7" wide for a tall foyer, and I don't have a big enough miter box to do it!

Crown moldings

Help how to my corners to match up?

You need to cut a compound angle to make the corners. The angle on the face is 22 1/2 (half
the 45 degrees that they are angled against the corner) and the angle on the edges is 45.

Crown Molding and plaster walls

Can anyone tell me the best way to attach crown molding to plaster walls...?

I had problems finding the studs and keeping the molding straight. I made angle brackets,2X4 with the correct wall angle , attached them to the studs, and then just nailed the Crown to the brackets, Much easier to deal with. At the corners or joints, I liquid nailed the brackets up and this gave me a good nailer even without studs. Crown Molding is not for the faint hearted, but this made it much more manageable.

Another idea: A stud finder with a 2 inch nail finder.
Still another thought: They are attached the same way to drywall walls. You have to locate the studs and ceiling joists and fasten the molding to them.

Crown Molding

OK - I have read different suggestions regarding installing crown molding on an inside corner. Most say something like "the first piece is blunt against the wall, the second is a miter cut, then use a coping saw and follow the pattern of the molding to make the fit". My molding is quite intricate - I'm not that good with a coping saw. Am I missing something or do I need to hire a professional carpenter?

The first cut needs to be turned up side down and cut at a 45 degree, then you can scribe the moulding with a coping saw to the cut needed. When you flip over the moulding (right side up) the moulding will butt up to the molding. If the moulding is going to be painted just 45 degree the joint upside down and fill the inside cornor with putty .

When hanging the molding I heard it was best to cope it to fit and inside
corner. Don't quite understand how to do that.
I am not sure that you need to cope cove molding for inside corners. I think a butt joint with the compound miter
cut to account for the angle of the cove (45 degrees) and the corner will work correctly. Practice this cut with
some scrap to make sure you are cutting it right... but it should be 22 1/2 degrees across the face and 45 degrees
on the edge.

To cope the joint you cut one flat and square and the other one is cut with a cut that matches
the contour of the other. By placing the one piece up against the other you can draw the outline you will cut with
a coping saw such that when it is cut and placed against the other piece, it matches up with the contoured face
of the other.

If the molding you are mounting is cove molding and it attached at an angle to the wall... then cut the compound
miter... if it is flat you can cope the end to fit flush.

The baseboard molding in my rooms have separted away from the floors. How
can I begin to fix this?

But WHY has your baseboard molding separated from the floor? How old is your house? And
what floor has this problem occurred on?

If you wish to eliminate the gap, first you should find out why it is there. If the floor has settled, it may be
wiser to have the floor jacked back up, and the floor support below checked out and firmed up. This separation should probably only occur on a interior wall and as the floor sags, the wall remained in place.

If the floor is supported ok, and you will leave it that way, then the molding can be removed (carefully pulling it away from the wall) and moved down and renailed. Nails should be pulled out of the wood from the back to keep the front of the board from splintering, and new nails used in new holes.